I can't edit anymore, but it's worth mentioning... Stuffing the tube more made a big improvement. It maybe stiffened up my flex-tube, and definitely evened out the frequencies.. They sound great! Much better than before the ff85's were in their own chamber. The sound fills the room more now... Not sure exactly how to describe it, but the full-range magic is there, stereo imaging is great. Maybe that simply means I'm getting them dialed in properly.

-Just in case it isn't clear, that tube is sealed around the back of the ff85k hole and curves around to the hole where the mid driver used to be located.

tubes are not the best to use for mid chamber, so I guess the stuffing helps a bit
and further, routing it back to the front, like you say it does, means you have unintentionall 'phased signal' from the tube
or maybe I have misunderstood, and the 'old' midchamber is closed
means it could work as 'acoustic buffer', which might be positive

Thanks, I was wondering about that (phase)... I have been thinking it would be better out the back. I'm just not prepared to cut a hole.. And, I liked the idea of using the original hole that's in the box, but that's silly.

It's definitely in 'alpha' stage, and these aren't the materials I will use in the end!

I was thinking about phase.. And could be completely wrong, so I 1/2 expect a "NO", response..
Could I extend the tube below the outlet (the old mid-driver location), and then bring it back up, and out, similar to a folded horn? Would that correct it somewhat?

Lifting the speaker from the floor and slightly tilted is true for all (or most) speakers, isn't it? I'll try it.. It helps my full range horns.

Thank you again. That is exactly what I ended up w/, going by ear. It is dense in that tube. But, maybe the whole curved and out the front thing is pointless or even detrimental. I'll keep trying different things when I've got time.
It's amazing what I've turned these trash speaker cabinets in to. All I had to purchase was a pair of woofers. (Thanks to several old projects worth of leftover parts)
I also still want to lower the xover, but that will be a relatively expensive purchase (for this cheap project) so I want to think about that more for a while.